Abstract:[Objective] To explore the clinical outcomes of anatomic reconstruction of ankle lateral collateral ligament with partial pero- neal longus tendon autograft for chronic lateral ankle instability. [Methods] A retrospective study was performed on 19 patients who under- went anatomical reconstruction of ankle lateral collateral ligament with partial autograft of peroneus longus tendon for chronic lateral ankle instability from January 2019 to April 2021. The perioperative, follow- up and imaging data were summarized. [Results] All the patients were successfully operated on with operative time of (100.42±18.15) min, intraoperative blood loss of (47.63±13.88) ml, and excellent inci- sion healing. At the latest interview lasted for (20.79±5.90) months the VAS score significantly decreased (P<0.05) , whereas the AOFAS ankle-hindfoot score significantly increased compared with those preoperatively (P<0.05) . Although there was no significant change in dor- siflexion plantarflexion range of motion (ROM) (P>0.05) , the ROM of eversion-inversion significantly decreased at the latest follow- up compared with those preoperatively (P<0.05) . In term of patients' satisfaction, 10 cases (52.63%) were very satisfied, 7 cases (36.84%) were satisfied, 2 cases (10.53%) of the fair. Radiographically, the talus title (TT) and anterior talar translation (ATT) on radiographs under stress at the latest follow-up significantly reduced compared with those before operation (P<0.05) . The MRI or musculoskeletal ultrasound showed good continuity of graft tendon and no abnormal edema signal in 16 patients of them at the last follow-up. [Conclusion] Anatomical reconstruction of the ankle lateral collateral ligament with partial peroneus longus tendon autograft is a safe, effective and feasible method for the treatment of chronic lateral ankle instability.